Fever is also known as hyperthermia, pyrexia, or elevated temperature. It describes a body temperature that's higher than normal. Fever can affect children and adults. A short-term increase in body temperature can help your body fight off illness.

It is normal to have periods of low energy when one needs to rest and recuperate. However, if low energy persists and a person continually feels sluggish, disinterested in life, and has low energy, the situation should be investigated by a physician.

Oliguria is the medical term for a decreased output of urine. Oliguria is considered to be a urinary output of less than 400 milliliters, which is less than about 13.5 ounces, over the course of 24 hours.

Blue lips may represent a type of cyanosis caused by a lower level of circulating oxygen in the red blood cells. It may also represent a high level of an abnormal form of hemoglobin in the circulation.

Blue fingernails may represent a type of cyanosis caused by a lower level of lack of circulating oxygen in the red blood cells. It may also represent a high level of an abnormal form of hemoglobin in the circulation.

A bruise or "contusion" appears on the skin when it has suffered trauma such as a cut or a blow to the area. The injury causes tiny blood vessels called capillaries to burst, and the blood gets trapped below the skin